The present invention relates to open chain alkoxyamine compounds, a polymerizable composition comprising a) at least one ethylenically unsaturated monomer and b) at least one open chain alkoxyamine compound. Further aspects of the present invention are a process for polymerizing ethylenically unsaturated monomers, and the use of open chain alkoxyamine compounds for controlled polymerization. The intermediate N-oxyl derivatives, a composition of the N-oxyl derivatives with ethylenically unsaturated monomers and a free radical initiator X., as well as a process for polymerization are also subjects of the present invention.
The compounds of the present invention provide polymeric resin products having low polydispersity. The polymerization process proceeds with enhanced monomer to polymer conversion efficiency. In particular, this invention relates to stable free radical-mediated polymerization processes which provide homopolymers, random copolymers, block copolymers, multiblock copolymers, graft copolymers and the like, at enhanced rates of polymerization and enhanced monomer to polymer conversions.
Polymers or copolymers prepared by free radical polymerization processes inherently have broad molecular weight distributions or polydispersities which are generally higher than about four. One reason for this is that most of the free radical initiators have half lives that are relatively long, ranging from several minutes to many hours, and thus the polymeric chains are not all initiated at the same time and the initiators provide growing chains of various lengths at any time during the polymerization process. Another reason is that the propagating chains in a free radical process can react with each other in processes known as combination and disproportionation, both of which are irreversibly chain-terminating reaction processes. In doing so, chains of varying lengths are terminated at different times during the reaction process, resulting in resins consisting of polymeric chains which vary widely in length from very small to very large and which thus have broad polydispersities. If a free radical polymerization process is to be used for producing narrow molecular weight distributions, then all polymer chains must be initiated at about the same time and termination of the growing polymer-chains by combination or disproportionation processes must be avoided.
Conventional radical polymerization reaction processes pose various significant problems, such as difficulties in predicting or controlling the molecular weight, the polydispersity and the modality of the polymers produced. Furthermore, free radical polymerization processes in bulk of the prior art are difficult to control because the polymerization reaction is strongly exothermic and an efficient heat removal in the highly viscous polymer is mostly impossible. The exothermic nature of the prior art free radical polymerization processes often severely restricts the concentration of reactants or the reactor size upon scale-up.
Due to the above mentioned uncontrollable polymerization reactions, gel formation in conventional free radical polymerization processes are also possible and cause broad molecular weight distributions and/or difficulties during filtering, drying and manipulating the product resin.
U.S. Pat. No. 4,581,429 to Solomon et al., issued Apr. 8, 1986, discloses a free radical polymerization process which controls the growth of polymer chains to produce short chain or oligomeric homopolymers and copolymers, including block and graft copolymers. The process employs an initiator having the formula (in part) Rxe2x80x2Rxe2x80x3Nxe2x80x94Oxe2x80x94X, where X is a free radical species capable of polymerizing unsaturated monomers. The reactions typically have low conversion rates. Specifically mentioned radical Rxe2x80x2Rxe2x80x3Nxe2x80x94O. groups are derived from 1,1,3,3 tetraethylisoindoline, 1,1,3,3 tetrapropylisoindoline, 2,2,6,6 tetramethylpiperidine, 2,2,5,5 tetramethylpyrrolidine or di-t-butylamine. However, the suggested compounds do not fulfill all requirements. Particularly the polymerization of acrylates does not proceed fast enough and/or the monomer to polymer conversion is not as high as desired.
EP-A-735 052 discloses a method for preparing thermoplastic polymers of narrow poly-dispersities by free radical-initated polymerization, which comprises adding a free radical initiator and a stable free radical agent to the monomer compound.
This method has the disadvantage that uncontrollable recombinations of initiator radicals occur immediately after their formation, thus producing variable ratios between initiator radicals and stable free radicals. Consequently there is no good control of the polymerization process.
There is therefore still a need for polymerization processes for the preparation of narrow polydispersity polymeric resins with defined molecular weights using the economical free radical polymerization techniques. These polymerization processes will also control the physical properties of the polymers such as viscosity, hardness, gel content, processability, clarity, high gloss, durability, and the like.
The polymerization processes and resin products of the present invention are useful in many applications, including a variety of specialty applications, such as for the preparation of block copolymers which are useful as compatibilizing agents for polymer blends, or dispersing agents for coating systems or for the preparation of narrow molecular weight resins or oligomers for use in coating technologies and thermoplastic films or as toner resins and liquid immersion development ink resins or ink additives used for electrophotographic imaging processes.
Surprisingly, it has now been found that it is possible to overcome the afore mentioned shortcomings of the prior art by providing a polymerizable composition containing specific initiator compounds. Polymerization of the composition results in a polymer or copolymer of narrow polydispersity and a high monomer to polymer conversion even at relatively low temperatures and at short reaction times, making the polymerization process particularly suitable for industrial applications. The resulting copolymers are of high purity and in many cases colorless, therefore not requiring any further purification.
The present invention relates to open chain alkoxyamine compounds which have no or at most only one electron withdrawing group at the C-atom in xcex1-position to the nitrogen atom. These compounds are stable enough at low temperature and decompose readily at elevated temperature. Therefore being almost ideally suitable for controlled polymerizations.
One object of the present invention is a compound according to formula Ia, Ib or Ic 
wherein
Y is O or CH2;
Q is O or NR20, wherein R20 is hydrogen or C1-C18alkyl;
R1 is tertiary C4-C18alkyl or phenyl, which are unsubstituted or substituted by halogen, OH, COOR21 or C(O)xe2x80x94R22 wherein R21 is hydrogen, a alkali metal atom or C1-C18alkyl and R22 is C1-C18alkyl; or
R1 is C5-C12cycloalkyl, C5-C12cycloalkyl which is interrupted by at least one O or N atom, a polycyclic alkyl radical or a polycyclic alkyl radical which is interrupted by at least one O or N atom;
R2 and R3 are independently C1-C18alkyl, benzyl, C5-C12cycloalkyl or phenyl, which are unsubstituted or substituted by halogen, OH, COOR21 or C(O)xe2x80x94R22 or together with the carbon atom form a C5-C12cycloalkyl ring;
if Y is O,
R4 and R12 are OH, O(alkali-metal) C1-C18alkoxy, benzyloxy, NR23R24, wherein R23 and R24 are independently from each other hydrogen, C1-C18alkyl or phenyl, which are unsubstituted or substituted by halogen, OH, COOR21 or C(O)xe2x80x94R22;
if Y is CH2,
R4 is OH, C1-C18alkoxy, benzyloxy, Oxe2x80x94C(O)xe2x80x94(C1-C18)alkyl or NR23R24;
R12 is a group C(O)R25, wherein R25 is OH, C1-C18alkoxy, benzyloxy, NR23R24, wherein R23 and R24 are independently from each other hydrogen, C1-C18alkyl or phenyl, which are unsubstituted or substituted by halogen, OH, COOR21 or C(O)xe2x80x94R22;
R5, R6, R7 and R8 are independently of each other C1-C18alkyl, C5-C12cycloalykyl or phenyl, with the proviso that not more than two are phenyl; or
R5 and R6 and/or R7 and R8 together with the carbon atom form a C5-C12cycloalkyl ring;
R9 and R10 are independently from each other hydrogen, formyl, C2-C18alkylcarbonyl, benzoyl, C1-C18alkyl, C5-C12cycloalkyl, C5-C12cycloalkyl which is interrupted by at least one O or N atom, benzyl or phenyl which are unsubstituted or substituted by halogen, OH, COOR21 or C(O)xe2x80x94R22;
R11, is formyl, C2-C18alkylcarbonyl, benzoyl, C1-C18alkyl, C5-C12cycloalkyl, C5-C12cycloalkyl which is interrupted by at least one O or N atom, benzyl or phenyl which are unsubstituted or substituted by halogen, OH, COOR21 or C(O)xe2x80x94R22; and
X represents a group having at least one carbon atom and is such that the free radical X. derived from X is capable of initiating polymerization of ethylenically unsaturated monomers.
Halogen is Fluorine, Chlorine, Bromine or Iodine, preferably Chlorine or Bromine.
The alkyl radicals in the various substituents may be linear or branched. Examples of alkyl containing 1 to 18 carbon atoms are methyl, ethyl, propyl, isopropyl, butyl, 2-butyl, isobutyl, t-butyl, pentyl, 2-pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, t-octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, hexadecyl and octadecyl. C5-C12cycloalkyl is typically, cyclopentyl, methylcyclopentyl, dimethylcyclopentyl, cyclohexyl, methylcyclohexyl.
Cycloalkyl which is interrupted by at least one O or N atom is for example 2-tetrahydropyran-yl, tetrahydrofurane-yl, 1,4 dioxan-yl, pyrrolidin-yl, tetrahydrothiophen-yl, pyrazolidin-yl, imidazolidin-yl, butyrolactone-yl, caprolactame-yl
Examples for alkali metal are lithium, sodium or potassium.
C1-C18 alkoxy is for example methoxy, ethoxy, propoxy, butoxy, pentoxy, octoxy, dodecyloxy or octadecyloxy.
C2-C18 alkylcarbonyl is for example acetyl, propionyl, butyryl, pentylcarbonyl, hexylcarbonyl or dodecylcarbonyl.
Polycyclic alkyl radicals which may also be interrupted by at least one oxygen or nitrogen atom are for example adamantane, cubane, twistane, norbornane, bypyclo[2.2.2]octane bycyclo[3.2.1]octane, hexamethylentetramine (urotropine) or a group 
Preferably X is selected from the group consisting of xe2x80x94CH2-aryl, 
xe2x80x94CH2xe2x80x94CH2-aryl, 
(C5-C6cycloalkyl)2CCN, (C1-C12alkyl)2CCN, xe2x80x94CH2CHxe2x95x90CH2, (C1-C12)alkyl-CR30xe2x80x94C(O)xe2x80x94(C1-C12)alkyl, (C1-C12)alkyl-CR30xe2x80x94C(O)xe2x80x94(C6-C10)aryl, (C1-C12)alkyl-CR30xe2x80x94C(O)xe2x80x94(C1-C12)alkoxy, (C1-C12)alkyl-CR30xe2x80x94C(O)-phenoxy, (C1 -C12)alkyl-CR30xe2x80x94C(O)xe2x80x94N-di(C1-C12)alkyl, (C1-C12)alkyl-CR30xe2x80x94COxe2x80x94NH(C1-C12)alkyl, (C1-C12)alkyl-CR30xe2x80x94COxe2x80x94NH2, xe2x80x94CH2CH=CHxe2x80x94CH3, xe2x80x94CH2xe2x80x94C(CH3)xe2x95x90CH2, xe2x80x94CH2xe2x80x94CHxe2x95x90CH-phenyl, 
(C1-C12)alkyl-CR30xe2x80x94CN, 
wherein
R30 is hydrogen or C1-C12alkyl;
the aryl groups are phenyl or naphthyl, which are unsubstituted or substituted with C1-C12alkyl, halogen, C1-C12alkoxy, formyl, C2-C12alkylcarbonyl, glycidyloxy, OH, xe2x80x94COOH or xe2x80x94COOC1-C12alkyl.
More preferably X is selected from the group consisting of xe2x80x94CH2-phenyl, CH3CH-phenyl, (CH3)2C-phenyl, (C5-C6cycloalkyl)2CCN, (CH3)2CCN, xe2x80x94CH2CHxe2x95x90CH2, CH3CHxe2x80x94CHxe2x95x90CH2(C1-C8alkyl)CR30xe2x80x94C(O)-phenyl, (C1-C8)alkyl-CR30xe2x80x94C(O)xe2x80x94(C1-C8)alkoxy, (C1-C8)alkyl-CR30xe2x80x94C(O)xe2x80x94(C1-C8)alkyl, (C1-C8)alkyl-CR30xe2x80x94C(O)xe2x80x94N-di(C1-C8)alkyl, (C1-C8)alkyl-CR30xe2x80x94C(O)xe2x80x94NH(C1-C8)alkyl, (C1-C8)alkyl-CR30xe2x80x94C(O)xe2x80x94NH2, (C1-C12)alkyl-CR30xe2x80x94CN, wherein R30 is hydrogen or (C1-C8)alkyl.
Most preferably X is selected from the group consisting of xe2x80x94CH2-phenyl, CH3CH-phenyl, (CH3)2C-phenyl, (C5-C6cycloalkyl)2CCN, (CH3)2CCN, xe2x80x94CH2CHxe2x95x90CH2, CH3CHxe2x80x94CHxe2x95x90CH2(C1-C4alkyl)CR30xe2x80x94C(O)-phenyl, (C1-C4)alkyl-CR30xe2x80x94C(O)xe2x80x94(C1-C4)alkoxy, (C1-C4)alkyl-CR30xe2x80x94C(O)xe2x80x94(C1-C4)alkyl, (C1-C4)alkyl-CR30xe2x80x94C(O)xe2x80x94N-di(C1-C4)alkyl, (C1-C4)alkyl-CR30xe2x80x94C(O)xe2x80x94NH(C1-C4)alkyl-CR30xe2x80x94C(O)xe2x80x94NH2, wherein R30 is hydrogen or (C1-C4)alkyl.
Preferred compounds are those, wherein
Y and Q are O.
A preferred subgroup of compounds are those of formula (Ia), wherein Y is Q;
R1 is tertiary C4-C18alkyl, C5-C12cycloalkyl, C5-C12cycloalkyl which is interrupted by at least one O or N atom or a polycyclic alkyl radical;
R2 and R3 are independently C1-C10alkyl, benzyl, phenyl, which are unsubstituted or substituted by halogen, OH, COOR21 or C(O)xe2x80x94R22 or together with the carbon atom form a C5-C12cycloalkyl ring;
R4 is C1-C18alkoxy, benzyloxy or NR23R24, wherein R23 and R24 are independently of each other hydrogen or C1-C18alkyl.
Amongst this subgroup those compounds of formula (Ia) are particularly preferred, wherein
R1 is tertiary C4-C8alkyl;
R2 and R3 are methyl, ethyl or together with the carbon atom form a C5-C6cycloalkyl ring;
R4 is C1-C18alkoxy, benzyloxy or NR23R24, wherein R23 and R24 are independently of each other hydrogen or C1-C8alkyl.
The definition and preferences for X apply also for the subgroups according to formula (Ia).
Another preferred subgroup of compounds are those of formula (Ib), wherein Q is O;
R5, R6, R7 and R8 are independently of each other C1-C10alkyl, C5-C12cycloalkyl; or
R5 and R6 and/or R7 and R8 together with the carbon atom form a C5-C12cycloalkyl ring;
R9 and R10 are independently of each other formyl, C2-C18alkylcarbonyl, benzoyl, C1-C18alkyl, benzyl or phenyl.
Within the subgroup of compounds of formula (Ib) those are particularly preferred, wherein
Q is O;
R5, R6, R7 and R8 are independently of each other methyl, ethyl; or
R5 and R6 and/or R7 and R8 together with the carbon atom form a C5-C6cycloalkyl ring;
R9 and R10 are independently of each other formyl, C2-C8alkylcarbonyl, benzoyl, C1-C8alkyl, benzyl or phenyl.
The definition and preferences for X apply also for the subgroups according to formula (Ib).
Still another preferred subgroup of compounds are those of formula (Ic), wherein Y is O
R5, R6, R7 and R8 are independently of each other C1-C10alkyl, C5-C12cycloalkyl; or
R5 and R6 and/or R7 and R8 together with the carbon atom form a C5-C12cycloalkyl ring;
R11 is formyl, C2-C18alkylcarbonyl, benzoyl, C1-C18alkyl, benzyl or phenyl and
R12 is OH, C1-C18alkoxy, benzyloxy, NR23R24, wherein R23 and R24 are independently of each other hydrogen, C1-C18alkyl or phenyl.
Within the subgroup of compounds of formula (Ic) those are particularly preferred, wherein Y is O
R5, R6, R7 and R8 are independently of each other methyl, ethyl; or
R5and R6 and/or R7 and R8 together with the carbon atom form a C5-C6cycloalkyl ring;
R11 is formyl, C2-C18alkylcarbonyl, benzoyl, C1-C18alkyl, benzyl or phenyl and
R12 is OH, C1-C18alkoxy, benzyloxy, NR23R24, wherein R23 and R24 are independently of each other hydrogen or C1-C18alkyl.
Another object of the present invention is a polymerizable composition, comprising
a) at least one ethylenically unsaturated monomer or oligomer, and
b) at least one compound of formula (Ia), (Ib) or (Ic).
Typically the ethylenically unsaturated monomer or oligomer is selected from the group consisting of ethylene, propylene, n-butylene, i-butylene, styrene, substituted styrene, conjugated dienes, acrolein, vinyl acetate, vinylpyrrolidone, vinylimidazole, maleic anhydride, (alkyl)acrylic acidanhydrides, (alkyl)acrylic acid salts, (alkyl)acrylic esters, (meth)acrylo-nitriles, (alkyl)acrylamides, vinyl halides or vinylidene halides.
Preferred ethylenically unsaturated monomers are ethylene, propylene, n-butylene, i-butylene, isoprene, 1,3-butadiene, xcex1-C5-C18alkene, styrene, xcex1-methyl styrene, p-methyl styrene or a compound of formula CH2xe2x95x90C(Ra)xe2x80x94(Cxe2x95x90Z)xe2x80x94Rb, wherein Ra is hydrogen or C1-C4alkyl, Rb is NH2, Oxe2x88x92(Me+), glycidyl, unsubstituted C1-C18alkoxy, C2-C100alkoxy interrupted by at least one N and/or O atom, or hydroxy-substituted C1-C18alkoxy, unsubstituted C1-C18alkylamino, di(C1-C18alkyl)amino, hydroxy-substituted C1-C18alkylamino or hydroxy-substituted di(C1-C18alkyl)amino, xe2x80x94Oxe2x80x94CH2xe2x80x94CH2xe2x80x94N(CH3)2 or xe2x80x94Oxe2x80x94CH2xe2x80x94CH2xe2x80x94N+H(CH3)2 Anxe2x88x92;
Anxe2x88x92 is a anion of a monovalent organic or inorganic acid;
Me is a monovalent metal atom or the ammonium ion.
Z is oxygen or sulfur.
Examples for Ra as C2-C100alkoxy interrupted by at least one O atom are of formula 
wherein Rc is C1-C25alkyl, phenyl or phenyl substituted by C1-C18alkyl, Rd is hydrogen or methyl and v is a number from 1 to 50. These monomers are for example derived from non ionic surfactants by acrylation of the corresponding alkoxylated alcohols or phenols. The repeating units may be derived from ethylene oxide, propylene oxide or mixtures of both.
Further examples of suitable acrylate or methacrylate monomers are given below. 
Anxe2x88x92, wherein Anxe2x88x92 and Ra have the meaning as defined above and Re is methyl or benzyl. Anxe2x88x92is preferably Clxe2x88x92, Brxe2x88x92or xe2x88x92O3Sxe2x80x94CH3.
Further acrylate monomers are 
Examples for suitable monomers other than acrylates are 
Preferably Ra is hydrogen or methyl, Rb is NH2, gycidyl, unsubstituted or with hydroxy substituted C1-C4alkoxy, unsubstituted C1-C4alkylamino, di(C1-C4alkyl)amino, hydroxy-substituted C1-C4alkylamino or hydroxy-substituted di(C1-C4alkyl)amino;and Z is oxygen.
Particularly preferred ethylenically unsaturated monomers are styrene, methylacrylate, ethylacrylate, butylacrylate, isobutylacrylate, tert. butylacrylate, hydroxyethylacrylate, hydroxypropylacrylate, dimethylaminoethylacrylate, glycidylacrylates, methyl(meth)acrylate, ethyl(meth)acrylate, butyl(meth)acrylate, hydroxyethyl(meth)acrylate, hydroxypropyl(meth)acrylate, dimethylaminoethyl(meth)acrylate, glycidyl(meth)acrylates, acrylonitrile, acrylamide, methacrylamide or dimethylaminopropyl-methacrylamide.
It is also possible to enhance the rate of polymerization or copolymerization of slowly polymerizing monomers such as for example of the class of methacrylates, in particular methylmethacrylate by the addition of more readily polymerizable comonomers such as acrylates. Typical examples are the polymerization or copolymerization of methylmethacrylate in the presence of methylacrylate or butylacrylate.
Typical slowly polymerizing methacrylates are methyl(meth)acrylate, ethyl(meth)acrylate, butyl(meth)acrylate, hydroxyethyl(meth)acrylate, hydroxypropyl(meth)acrylate, dimethylaminoethyl(meth)acrylate, glycidyl(meth)acrylates, methacrylamide or dimethylaminopropyl-methacrylamide. The polymerization of these methacrylates can be enhanced by the addition of the corresponding acrylates.
Preferred is a composition, wherein the ethylenically unsaturated monomer is a mixture of a methacrylate and an acrylate.
The amounts of readily polymerizable comonomers range typically from 5 parts to 95 and the slowly polymerizable monomers range from 95 to 5 parts respectively.
The initiator compound is preferably present in an amount of from 0.1 mol-% to 30 mol-%, more preferably in an amount of from 0.1 mol-% to 20 mol-%, and most preferably in an amount of from 0.5 mol-% to 10 mol-% based on the monomer or monomer mixture.
A further object of the present invention is a process for preparing an oligomer, a cooligomer, a polymer or a copolymer (block or random) by free radical polymerization of at least one ethylenically unsaturated monomer or oligomer, which comprises (co)polymerizing the monomer or monomers/oligomers in the presence of at least one initiator compound of formula (Ia), (Ib) or (Ic) under reaction conditions capable of effecting scission of the Oxe2x80x94C bond to form two free radicals, the radical .X being capable of initiating polymerization.
Typically the scission of the Oxe2x80x94C bond is effected by ultrasonic treatment, heating or exposure to electromagnetic radiation, ranging from xcex3 to microwaves.
Preferably the scission of the Oxe2x80x94C bond is effected by heating and takes place at a temperature of between 50xc2x0 C. and 160xc2x0 C., more preferably between 80xc2x0 C. and 150xc2x0 C.
The process may be carried out in the presence of an organic solvent or in the presence of water or in mixtures of organic solvents and water. Additional cosolvents or surfactants, such as glycols or ammonium salts of fatty acids, may be present. Other suitable cosolvents are described hereinafter.
Preferred processes use as little solvents as possible. In the reaction mixture it is preferred to use more than 30% by weight of monomer and initiator, particularly preferably more than 50% and most preferrably more than 80%. In many cases it is possible to polymerize without any solvent.
If organic solvents are used, suitable solvents or mixtures of solvents are typically pure alkanes (hexane, heptane, octane, isooctane), hydrocarbons (benzene, toluene, xylene), halogenated hydrocarbons (chlorobenzene), alkanols (methanol, ethanol, ethylene glycol, ethylene glycol monomethyl ether), esters (ethyl acetate, propyl, butyl or hexyl acetate) and ethers (diethyl ether, dibutyl ether, ethylene glycol dimethyl ether), or mixtures thereof.
The aqueous polymerization reactions can be supplemented with a water-miscible or hydrophilic cosolvent to help ensure that the reaction mixture remains a homogeneous single phase throughout the monomer conversion. Any water-soluble or water-miscible cosolvent may be used, as long as the aqueous solvent medium is effective in providing a solvent system which prevents precipitation or phase separation of the reactants or polymer products until after all polymerization reactions have been completed. Exemplary cosolvents useful in the present invention may be selected from the group consisting of aliphatic alcohols, glycols, ethers, glycol ethers, pyrrolidines, N-alkyl pyrrolidinones, N-alkyl pyrrolidones, polyethylene glycols, polypropylene glycols, amides, carboxylic acids and salts thereof, esters, organosulfides, sulfoxides, sulfones, alcohol derivatives, hydroxyether derivatives such as butyl carbitol or cellosolve, amino alcohols, ketones, and the like, as well as derivatives thereof and mixtures thereof. Specific examples include methanol, ethanol, propanol, dioxane, ethylene glycol, propylene glycol, diethylene glycol, glycerol, dipropylene glycol, tetrahydrofuran, and other water-soluble or water-miscible materials, and mixtures thereof. When mixtures of water and water-soluble or water-miscible organic liquids are selected as the aqueous reaction media, the water to cosolvent weight ratio is typically in the range of about 100:0 to about 10:90.
The process is particularly useful for the preparation of block copolymers.
Block copolymers are, for example, block copolymers of polystyrene and polyacrylate (e.g., poly(styrene-co-acrylate) or poly(styrene-co-acrylate-co-styrene). They are useful as adhesives or as compatibilizers for polymer blends or as polymer toughening agents. Poly(methylmethacrylate-co-acrylate) diblock copolymers or poly(methylacrylate-co-acrylate-co-methacrylate) triblock copolymers) are useful as dispersing agents for coating systeme, as coating additives (e.g. rheological agents, compatibilizers, reactive diluents) or as resin component in coatings(e.g. high solid paints) Block copolymers of styrene, (meth)acrylates and/or acrylonitrile are useful for plastics, elastomers and adhesives.
Furthermore, block copolymers of this invention, wherein the blocks alternate between polar monomers and non-polar monomers, are useful in many applications as amphiphilicsurfactants or dispersants for preparing highly uniform polymer blends.
The (co)polymers of the present invention may have a number average molecular weight from 1 000 to 400 000 g/mol, preferably from 2 000 to 250 000 g/mol and, more preferably, from 2 000 to 200 000 g/mol. The number average molecular weight may be determined by size exclusion chromatography (SEC), gel permeation chromatography (GPC), matrix assisted laser desorption/ionization mass spectrometry (MALDI-MS) or, if the initiator carries a group which can be easily distinguished from the monomer(s), by NMR spectroscopy or other conventional methods.
The polymers or copolymers of the present invention have preferably a polydispersity of from 1.1 to 2, more preferably of from 1.2 to 1.8.
Thus, the present invention also encompasses in the synthesis novel block, multi-block, star, gradient, random, hyperbranched and dendritic copolymers, as well as graft copolymers.
The definitions and preferences for the different substituents given for the compounds, apply also for the composition and for the polymerization process. The polymers prepared by the present invention are useful for following applications: adhesives, detergents, dispersants, emulsifiers, surfactants, defoamers, adhesion promoters, corrosion inhibitors, viscosity improvers, lubricants, rheology modifiers, thickeners, crosslinkers, paper treatment, water treatment, electronic materials, paints, coatings, photography, ink materials, imaging materials, superabsorbants, cosmetics, hair products, preservatives, biocide materials or modifiers for asphalt, leather, textiles, ceramics and wood.
Because the present polymerizaton is a xe2x80x9clivingxe2x80x9d polymerization, it can be started and stopped practically at will. Furthermore, the polymer product retains the functional alkoxyamine group allowing a continuation of the polymerization in a living matter. Thus, in one embodiment of this invention, once the first monomer is consumed in the initial polymerizing step a second monomer can then be added to form a second block on the growing polymer chain in a second polymerization step. Therefore it is possible to carry out additional polymerizations with the same or different monomer(s) to prepare multi-block copolymers.
Furthermore, since this is a radical polymerization, blocks can be prepared in essentially any order. One is not necessarily restricted to preparing block copolymers where the sequential polymerizing steps must flow from the least stabilized polymer intermediate to the most stabilized polymer intermediate, such as is the case in ionic polymerization. Thus it is possible to prepare a multi-block copolymer in which a polyacrylonitrile or a poly(meth)acrylate block is prepared first, then a styrene or butadiene block is attached thereto, and so on.
Furthermore, there is no linking group required for joining the different blocks of the present block copolymer. One can simply add successive monomers to form successive blocks.
A plurality of specifically designed polymers and copolymers are accessible by the present invention, such as star and graft (co)polymers as described, inter alia, by C. J. Hawker in Angew. Chemie, 1995, 107, pages 1623-1627, dendrimers as described by K. Matyaszewski et al. in Macrmolecules 1996, Vol 29, No. 12, pages 4167-4171, graft (co)polymers as described by C. J. Hawker et al. in Macromol. Chem. Phys. 198, 155-166(1997), random copolymers as described by C. J. Hawker in Macromolecules 1996, 29, 2686-2688, or diblock and triblock copolymers as described by N. A. Listigovers in Macromolecules 1996, 29, 8992-8993.
Still another object of the present invention is a compound according to formula IIa, IIb or IIc 
wherein
Y is O or CH2;
Q is O or NR20, wherein R20, is hydrogen or C1-C18alkyl;
R1 is tertiary C4-C18alkyl or phenyl, which are unsubstituted or substituted by halogen, OH, COOR21 or C(O)xe2x80x94R22 wherein R21 is hydrogen, a alkali metal atom or C1-C18alkyl and R22 is C1-C18alkyl; or
R1 is C5-C12cycloalkyl, C5-C12cycloalkyl which is interrupted by at least one O or N atom, a polycyclic alkyl radical or a polycyclic alkyl radical which is interrupted by at least one O or N atom;
R2 and R3 are independently C1-C18alkyl, benzyl, C5-C12cycloalkyl, phenyl, which are unsubstituted or substituted by halogen, OH, COOR21 or C(O)xe2x80x94R22 or together with the carbon atom form a C5-C12cycloalkyl ring;
if Y is O,
R4 and R12 are OH, O(alkali-metal) C1-C18alkoxy, benzyloxy, NR23R24, wherein R23 and R24 are independently from each other hydrogen, C1-C18alkyl or phenyl, which are unsubsbtuted or substituted by halogen, OH, COOR21 or C(O)xe2x80x94R22;
if Y is CH2,
R4 is OH, C1-C18alkoxy, benzyloxy, Oxe2x80x94C(O)xe2x80x94(C1-C18)alkyl or NR23R24;
R12 are a group C(O)R25, wherein R25 is OH, C1-C18alkoxy, benzyloxy, NR23R24, wherein R23 and R24 are independently from each other hydrogen, C1-C18alkyl or phenyl, which are unsubstituted or substituted by halogen, OH, COOR21 or C(O)xe2x80x94R22;
R5, R6, R7 and R8 are independently of each other C1-C18alkyl, C5-C12cycloalykyl or phenyl, with the proviso that not more than two are phenyl; or
R5 and R6 and/or R7 and R8 together with the carbon atom form a C5-C12cycloalkyl ring;
R9 and R10 are independently of each other hydrogen, formyl, C2-C18alkylcarbonyl, benzoyl, C1-C18alkyl, C5-C12cycloalkyl, C5-C12cycloalkyl which is interrupted by at least one O or N atom, benzyl or phenyl which are unsubstituted or substituted by halogen, OH, COOR21, or C(O)xe2x80x94R22; and
R11, is formyl, C2-C18alkylcarbonyl, benzoyl, C1-C18alkyl, C5-C12cycloalkyl, C5-C12cycloalkyl which is interrupted by at least one O or N atom, benzyl or phenyl which are unsubstituted or substituted by halogen, OH, COOR21 or C(O)xe2x80x94R22.
These compounds are intermediates of the title compounds and may also be used together with a radical source to effect polymerization of ethylenically unsaturated monomers or oligomers.
Consequently further objects of the invention are a polymerizable composition, comprising
a) at least one ethylenically unsaturated monomer or oligomer, and
b) at least one compound of formula (IIa), (IIb) or (IIc) and
c) a radical iniator X. capable of initiating polymerization of ethylenically unsaturated monomers and a process for preparing an oligomer, a cooligomer, a polymer or a copolymer (block or random) by free radical polymerization, which comprises subjecting above composition to heat or actinic radiation.
It is also possible and in some cases it may be advantageous to effect polymerization in the presence of a mixture of compounds of formula Ia, Ib, Ic and IIa, IIb, IIc. Typically the nitroxides of formula IIa, b, c are present in an amount of 0.1 to 10% by weight, based on the amount nitroxide ethers of formula Ia, b, c.
Preferably the nitroxides of formula IIa, b, c are present in an amount of 1 to 5% by weight, based on the amount nitroxide ethers of formula Ia, b, c.
Consequently another object of the present invention is a polymerizable composition comprising
a) at least one ethylenically unsaturated monomer or oligomer;
b) at least one compound of formula (Ia), (Ib) or (Ic) and
c) at least one compound of formula (IIa), (IIb) or (IIc).
The production of C-centered radicals X. is described, inter alia, in Houben Weyl, Methoden der Organischen Chemie, Vol. E 19a, pages 60-147. These methods can be applied in general analogy.
The source of radicals X. may be a bis-azo compound, a peroxide or a hydroperoxide.
Most preferably, the source of radicals X. is 2,2xe2x80x2-azobisisobutyronitrile, 2,2xe2x80x2-azobis(2-methylbutyronitrile), 2,2xe2x80x2-azobis(2,4-dimethylvaleronitrile), 2,2xe2x80x2-azobis(4-methoxy-2,4dimethylvaleronitrile), 1,1 xe2x80x2-azobis(1-cyclohexanecarbonitrile), 2,2xe2x80x2-azobis(isobutyramide)dihydrate, 2-phenylazo-2,4-dimethyl-4-methoxyvaleronitrile, dimethyl-2,2xe2x80x2-azobisisobutyrate, 2-carabamoylazo)isobutyronitrile, 2,2xe2x80x2-azobis(2,4,4-trimethylpentane), 2,2xe2x80x2-azobis(2-methylpropane), 2,2xe2x80x2-azobis(N,Nxe2x80x2-dimethyleneisobutyramidine), free base or hydrochloride, 2,2xe2x80x2-azobis(2-amidinopropane), free base or hydrochloride, 2,2xe2x80x2-azobis{2-methyl-N-[1,1-bis(hydroxymethyl)ethyl]propionamide} 2,2xe2x80x2-azobis{2-methyl-N-[1,1-bis(hydroxymethyl)-2-hydroxyethyl]propionamide.
Preferred peroxides and hydroperoxides are acetyl cyclohexane sulphonyl peroxide, diisopropyl peroxy dicarbonate, t-amyl perneodecanoate, t-butyl perneodecanoate, t-butyl perpivalate, t-amylperpivalate, bis(2,4-dichlorobenzoyl)peroxide, diisononanoyl peroxide, didecanoyl peroxide, dioctanoyl peroxide, dilauroyl peroxide, bis(2-methylbenzoyl)peroxide, disuccinic acid peroxide, diacetyl peroxide, dibenzoyl peroxide, t-butyl per 2-ethylhexanoate, bis-(4-chlorobenzoyl)-peroxide, t-butyl perisobutyrate, t-butyl permaleinate, 1,1-bis(t-butylperoxy)3,5,5-trimethylcyclohexane, 1,1-bis(t-butylperoxy)cyclohexane, t-butyl peroxy isopropyl carbonate, t-butyl perisononaoate, 2,5-dimethylhexane 2,5-dibenzoate, t-butyl peracetate, t-amyl perbenzoate, t-butyl perbenzoate, 2,2-bis(t-butylperoxy)butane, 2,2 bis(t-butylperoxy)propane, dicumyl peroxide, 2,5-dimethylhexane-2,5-di-t-butylperoxide, 3-t-butylperoxy 3-phenylphthalide, di-t-amyl peroxide, xcex1,xcex1xe2x80x2-bis(t-butylperoxy isopropyl) benzene, 3,5-bis(t-butylperoxy)3,5-dimethyl 1,2-dioxolane, di-t-butyl peroxide, 2,5-dimethylhexyne-2,5-di-t-butylperoxide, 3,3,6,6,9,9-hexamethyl 1,2,4,5-tetraoxa cyclononane, p-menthane hydroperoxide, pinane hydroperoxide, diisopropylbenzene mono-xcex1-hydroperoxide, cumene hydroperoxide or t-butyl hydroperoxide.
These compounds are commercially available.
If more than one radical source is used, a mixture of substitution patterns is obtainable.
The molar ratio of the radical source to the compound of formulae IIa, IIb or IIc may be from 1:10 to 10:1, preferably from 1:5 to 5:1 and more preferably from 1:2 to 2:1.
The present invention encompasses also a polymer or oligomer having attached at least one initiator group xe2x80x94X and at least one oxyamine group of formula (IIIa), (IIIb) or (IIIc) 
The use of a compound of formula (Ia), (Ib) or (Ic) or of a compound of formula (IIa), (IIb), or (IIc) for the polymerization of ethylenically unsaturated monomers or oligomers is a further object of the present invention.
Definitions and preferences mentioned above for the compounds apply for all objects of the invention.
The compounds of the present invention can be prepared by known methods.
A suitable way to prepare compounds of formula (Ia) is to start from the corresponding amines. The amines, wherein Y is O are known and can be prepared for example by ozonolysis of tert.-alkyl-allylamines according to U.S. Pat. No. 3,203,981
Alternatively reaction of a tertiary amine with CHCl3 and a ketone is also possible. J. T. Lai. in J. Org. Chem. 45, 3671 (1980).
Other possibilities are according to F. S. Guziec, F. F. Torres.: J. Org. Chem. 58, 1604 (1993) or the reaction of an aziridinone with an alcoholate according to H. Quast et. al.: Chem. Ber. 120, 217 (1987).
S. A. Kedik, E. G. Rozantsev, A. A. Usvyatsov.: Doklady Akademii Nauk SSSR, 257 (6), 1382 (1981) have reported on the oxidative cleavage of a 2,2,6,6-tetraalkyl-4-oxopiperidine, which also leads to the corresponding amines.
If Y is CH2 reduction of the corresponding carbonyl compound is possible as described by J. T. Lai.: Tet. Lett., 23, 595 (1982)):
To prepare compounds of formula (Ib) it is also suitable to start from the corresponding amines which are known per se. They can be prepared by reduction of 3,3,5,5-tetra-substituted-2-oxo-morpholinones and subsequent reaction of the alcohol groups (J. T. Lai.: Synthesis, 122 (1984)), or by reduction of the corresponding bis(cyanoalkyl)-amines according to J. V. Dubsky, W. D. Wensink.: Chem. Ber. 49, 1134 (1916).
The amines corresponding to formula (Ic) are accessible in the same manner, starting from the corresponding amines. The amines may be prepared according to S. A. Kedik, E. G. Rozantsev, A. A. Usvyatsov.: Doklady Akademii Nauk SSSR, 257 (6), 1382 (1981) or J. T. Lai.: Synthesis, 122 (1984).
The functional groups may be further reacted according to standard methods to obtain ethers or esters.
A further possibility is ring opening of 3,3,5,5-tetrasubstituted-2-oxo-morpholinones with primary or secondary amines. The resulting amides may be further functionalized.
The Oxidation of the amines to Nitroxides is well known and for example described in L. B. Volodarsky, V. A. Reznikov, V. I. Ovcharenko.: Synthetic Chemistry of Stable Nitroxides, CRC Press, Boca Raton 1994.
The NOR compounds are prepared for example by reacting the Nitroxides with free radicals. The radicals may be generated by scission of peroxy- or azo compounds as for example described by T. J. Connolly, M. V. Baldovi, N. Mohtat, J. C. Scaiano.: Tet. Lett. 37, 4919 (1996) or by I. Li, B. A. Howell et al.: Polym. Prepr. 36, 469 (1996).
Another possibility is a halogen atom transfer from a alkylhalogenide in the presence of Cu(I) as described by K. Matyjaszewski.: Macromol. Symp. 111, 47-61 (1996).) or a one electron oxidation as described by P. Stipa, L. Greci, P. Carloni, E. Damiani.: Polym. Deg. Stab. 55, 323 (1997))
Further possibilities are the O-alkylation of the corresponding hydroxylamine, as for example described by Said Oulad Hammouch, J. M. Catala.: Macromol. Rapid Commun. 17, 149-154 (1996), Meisenheinmer rearrangement of the corresponding N-Allyl-N-oxids as described by B. Walchuk et al.: Polymer Preprints 39, 296 (1998) or the reaction of a oxoammonium salt with a carbonyl compound, as described by Tan Ren, You-Cheng Liu, Qing-Xiang Guo.: Bull. Chem. Soc. Jpn. 69, 2935 (1996).